Researchers for Diabetes UK and Tesco found 132,000 people were diagnosed with the disease over the last year and a further 850,000 people are thought to have undiagnosed Type 2 diabetes.

Unless more is done to prevent the condition and help those who have it, experts fear the increase could see the NHS burdened with unsustainable costs, with huge implications for public health.

Every year 24,000 people with diabetes die earlier than expected in England and Wales, a situation that is expected to get even worse without urgent action.

Tesco and Diabetes UK have launched a partnership that will see the supermarket aim to raise £10 million for the charity to tackle the disease and help people affected by it.

The partnership will also fund the biggest ever public awareness campaign on Type 2 diabetes risk factors, aiming to reach the estimated seven million people at high risk.

Barbara Young, chief executive of Diabetes UK, said: "We are hugely concerned that the number of people diagnosed with diabetes has reached three million for the first time and there is no reason to think this will mark the end of what has been a rapid rise in the condition.

"Instead, all the projections suggest that the three million figure will be a grim staging post on the road towards a public health emergency and this unfolding tragedy is already putting huge pressure on the NHS and will have potentially devastating consequences for those people who develop the condition. But this is not inevitable.

"By identifying those at high risk of developing Type 2 diabetes, we can ensure they start getting support to make the kind of lifestyle changes that can help prevent it. And by making sure people who have Type 1 or Type 2 diabetes are already getting the care and support they need, we can help them avoid the devastating complications diabetes can cause."